From 6d14feffe699ad14c340a23043bd9d7904c06432 Mon Sep 17 00:00:00 2001
From: Alexandre Mutel <alexandre@unity3d.com>
Date: Sun, 3 Feb 2019 19:05:51 +0100
Subject: [PATCH] Fix invalid unicode scalar value

---
 src/SharpToml/Parsing/Lexer.cs   | 5 +++++
 src/SharpToml/Text/CharHelper.cs | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/src/SharpToml/Parsing/Lexer.cs b/src/SharpToml/Parsing/Lexer.cs
index b1bc4bd..57c40e4 100644
--- a/src/SharpToml/Parsing/Lexer.cs
+++ b/src/SharpToml/Parsing/Lexer.cs
@@ -821,6 +821,7 @@ private bool TryReadEscapeChar(ref TextPosition end)
                     case 'u':
                     case 'U':
                     {
+                        var start = _position;
                         end = _position;
                         var maxCount = _c == 'u' ? 4 : 8;
                         NextChar();
@@ -837,6 +838,10 @@ private bool TryReadEscapeChar(ref TextPosition end)
 
                         if (i == maxCount)
                         {
+                            if (!CharHelper.IsValidUnicodeScalarValue(value))
+                            {
+                                AddError($"Invalid Unicode scalar value [{value:X}]",start, start);
+                            }
                             _textBuilder.AppendUtf32((char32)value);
                             return true;
                         }
diff --git a/src/SharpToml/Text/CharHelper.cs b/src/SharpToml/Text/CharHelper.cs
index 4f0dcf2..42b0153 100644
--- a/src/SharpToml/Text/CharHelper.cs
+++ b/src/SharpToml/Text/CharHelper.cs
@@ -42,6 +42,11 @@ public static bool IsIdentifierContinue(char32 c)
             return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
         }
 
+        public static bool IsValidUnicodeScalarValue(char32 c)
+        {
+            return c >= 0 && c <= 0xD7FF || c >= 0xE000 && c < 0x10FFFF;
+        }
+
         public static bool IsDigit(char32 c)
         {
             return (c >= '0' && c <= '9');